1. Field of the Invention
The invention relates to a closing device where access authorization is detected by a dialog carried out electromagnetically between the transmission and reception units of an electric control device in the vehicle, on the one hand, and of a data carrier, on the other hand, which is external to the vehicle in the possession of the vehicle user. The field of application of the invention is directed especially to vehicles, but is also applicable for accessing safety zones etc.
2. Discussion of the Related Art
In the known device of this kind (WO 97/41322) the antenna as well as the transition and reception unit provided for the dialogue with the external data carrier are located in the interior of the vehicle. The reception and transmission properties of the vehicle-correlated antenna for the dialog with the user-correlated data carrier are unsatisfactory. The installation of the device part within the vehicle is cumbersome and replacement of elements of this device part as well as an exchange between different constructive types of these elements is complicated and therefore not practicable in practice.
It is an object of the invention to develop a closing device of the aforementioned kind such that it can be easily mounted and is optimized with respect to its functions. This is inventively achieved by arranging the antenna of the vehicle-correlated transmission and reception unit in the hand lever of the door handle.
Because according to the invention the antenna of the vehicle-correlated transmission and reception unit is already integrated in the door handle and is thus in an exposed location of the vehicle, an especially high electromagnetic sensitivity results. The transmission and reception of the electromagnetic signals between the data carrier and the vehicle is optimal. The door handle has the new function of being the support for the antenna and optionally of at least some further components of the vehicle-correlated transmission and reception unit. The previously required space within the vehicle and the installation of corresponding lines have thus been eliminated with the invention. The door handle and at least the antenna form a conveniently pre-mountable constructive unit. By attaching the door handle, which is required anyhow, the antenna is thus already positioned in its required position.
With the invention retrofitting of existing vehicles is also possible, as, for example, the exchange of inventively configured door handles of different constructive designs as they are mentioned in the dependent claims. With the arrangement in the door handle the path of signal transmission between the data carrier and the vehicle is minimized. The antenna characteristic of the antenna integrated into the handle is favorable. Because the door handle projects from the vehicle, an optimal detection area for the communication with the user-correlated data carrier is also provided.